Electronic and optical components are widely used in communication and sensing devices. Many such components comprise multiple integrated circuits constructed in different materials with different process integrated into a common device. Conventionally, multiple integrated circuits are assembled onto a common substrate such as a printed circuit board. The printed circuit board includes wiring that provides power, ground, and communication signals to the various multiple integrated circuits in the component.
A variety of methods are used for distributing electronically functional components over a substrate in the circuit board assembly industry including, for example, pick-and-place technologies for integrated circuits provided in a variety of packages such as pin-grid arrays, ball-grid arrays, and flip-chips. However, these techniques may be limited in the size of the integrated circuits that can be placed so that the integrated circuits and their packaging can be larger than is desired.
Another method for transferring active components from one substrate to another is described in U.S. Pat. No. 7,943,491. In an exemplary method, small integrated circuits are formed on a semiconductor wafer. The small integrated circuits, or chiplets, are released from the wafer by etching a layer formed beneath the circuits. A stamp (e.g., a PDMS stamp) is pressed against the wafer and the process side of the chiplets is adhered to the stamp. The chiplets are pressed against a destination substrate or backplane and adhered to the destination substrate. In another example, U.S. Pat. No. 8,722,458 entitled Optical Systems Fabricated by Printing-Based Assembly teaches transferring light-emitting, light-sensing, or light-collecting semiconductor elements from a wafer substrate to a destination substrate or backplane.
Integrated circuits are becoming ever denser and their associated packages ever smaller. Conventional photolithographic processes can enable single, very dense circuits in a specific technology and material (e.g., silicon) at a process resolution. However, it is often desirable to use different materials and processes for the components in order to improve performance or to reduce construction costs. For example, logic circuits often use CMOS circuits constructed in silicon semiconductor materials. Power components can be made in compound semiconductor materials, for example gallium arsenide, that have a higher electron mobility than silicon and can therefore have higher performance for power applications. Optical components are also made in compound semiconductor materials that are well suited for emitting or absorbing light.
Various materials typically have different costs and performance for a desired application and device. Moreover, processing costs, such as photolithographic costs, can differ for different materials and at different resolutions. It is advantageous, therefore, to select materials and a processing resolution that provide desired performance and costs for different components in a desired application and device.
There remains a challenge for integrating multiple heterogeneous components into a common device at high density and a need for improved structures and methods for the integration of heterogeneous components incorporating different materials with different processing resolutions and having different costs.